Conventionally, when a magnetic metal material is used as a thin plate, it is used by laminating a plurality of single thin plates. To laminate the thin plates, for example, when an amorphous metal ribbon is used as a magnetic metal material, since the thickness of the amorphous metal ribbon is from about 10 to 50 micro-meters, the surface of the amorphous metal ribbon is uniformly coated with a specific adhesive or impregnated in an adhesive and the resulting materials are laminated. Japanese Patent Application Laid-Open (JP-A) No. 1983-175654 (Patent Document 2) discloses a method for manufacturing a laminate wherein amorphous metal ribbons coated with an adhesive comprising as a main component a high heat resistant high molecular compound are stacked, pressed under a mandrel roll and then heat-adhered. However, when laminating the amorphous metal ribbons coated with a resin, only the film thickness is defined, but an adhered state is not specifically described.
Furthermore, in order to suppress eddy current between the magnetic metal thin plates, according to a conventional technique, the magnetic metal thin plates have been coated with a resin to actively achieve electrical insulation. In this manner, the electrical properties of the alternating current between the magnetic metal thin plates have been enhanced. For example, in U.S. Pat. No. 4,201,837 (Patent Document 2) a resin which has been used to improve the electrical properties of the alternating current is described as a preferred embodiment using a high molecular compound; however, this simply signifies insulating between metal layers with the high molecular compound. Further, in International Publication (WO) No. 03/060175 (Patent Document 3), a laminate of magnetic substrates comprising an amorphous metal and a high molecular compound is described. However, there is no specific disclosure regarding problems concerning exothermic property at times of use.
However, in any of these methods, in order to actively achieve electrical insulation, the film thickness of a high molecular compound layer must be increased to suppress the eddy current such that the metal thin plates do not come into contact with one another. In doing so, the proportion of the volume of a magnetic metal in a laminate (stacking factor) is lowered. Further, when a laminate is used for a magnetic core, it generates heat due to core loss. However, since the thermal conductivity of a resin is 10 to 100 times worse than that of a metal, the heat is unfavorably released via the resin layer. As a result, there has been a problem that as the resin layer gets thick, and heat is easily locked up in the laminate. When a magnetic laminate according to a conventional technique is used for a magnetic core, this becomes problematic from the viewpoints of miniaturization and higher power output, due to the rated power being reduced.    Patent Document: 1: JP-A No. 1983-175654A    Patent Document 2: U.S. Pat. No. 4,201,837    Patent Document 3: WO No. 03/060175